Hey all! I recently picked up this 20" ebike hub motor from a second hand store, and when i tried to find it online or use image search, i could not find any information relating to it apart from what i think is a model number on the cover and a logo. I believe it's between the 1000w - 3000w range due to the size and weight of the motor in the middle, and i think its brushed because it only has a red and black wire coming from it. I did hook it up to a ebike controller and battery and tried to test it but nothing happened. If someone could find the brand or the model from a website it would be great! (there is almost all the screws from one side missing, so i think someone has been inside before, but my end goal is to be able to fix it and get it running)
*SOLVED* Need help with unknown ebike hub motor
- Thread starter _Jo
- Start date
hillslayer@
1 kW
Why do you want to fix that, you realize you can buy a direct drive hub brand new off Amazon for less than 50 dollars.
gromike
10 kW
Maybe, but they seem to have jacked up the shipping charges.
Some of those have brushless controllers inside the hub. You might have to open it up to see.
I Did try hooking it up to a battery but it did not do anything, to take of the cover do i need a special tool?
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I also like to be resourceful with the little money i have
If there are no other wires besides the main red and black wires, it must be brushed.
If nothing happened with voltage applied, it's not a good sign. You can try measuring the resistance across the wires with a meter.
Hold the axle with something and try spinning it, then measure the resistance again.
If nothing happened with voltage applied, it's not a good sign. You can try measuring the resistance across the wires with a meter.
Hold the axle with something and try spinning it, then measure the resistance again.
You need a piece of scrap wood (that sheet of plywood looks too good). You’ll hold onto the rim with both hands, and bang the axle on the freewheel side down onto the scrap wood on the floor. The wood avoids damaging the axle and threads when you bang it on the floor. The cover, and stator will pop out on the top side, but be careful since the magnets are powerful and try to pull the stator back in with a lot of force (keep your fingers out of the way). You may need to remove the freewheel first.
EDIT: I’d remove the freewheel to make sure there isn’t a circlip on the axle on that side that would prevent the stator from popping out.
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So i have removed one side (the disk brake side) cover and this is what i found (also the axle cant be turned):
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A-DamW
10 kW
This is definitely a brushed motor.
My first ever ebike motor was a brushed 250w rated AOTEMA brand (sold by Green ebike kit I think) I got in like 2008-ish.
I still have it (pics below)
Brushed motors are generally easy to service if they have not been too abused.
This is probably what yours looks like under the stator;
Under the freewheel side;
Stator, the four red arrows point at the screws that set the timing for the brushes, probably don't mess with them;l
Stator, freewheel side, red arrows point to the carbon brushes, these slide on the copper segmented commutator.
This motor did not get a lot of heavy use, so the carbon brushes still have some service life left in them.
To service this motor; (or any dc brushed motor)
1. Disassemble, inspect the brush holders to make sure they are not burnt / melted / bent.
2. Check continuity of the windings with a multimeter, place probes on diametrically opposite commutator segments. (same position the brushes would be)
3. Check that the bearings rotate freely.
4. Inspect the commutator, it needs to be relatively flat, no excessive grooves or pitting. You can service the commutator by using a piece of fine sandpaper, or emery cloth(think 300 grit or finer) and polish it until it is nice and shiny.
EDIT; After polishing, run a razor blade or o-ring pick(or similar) between the commutator segments to clean them out.
5. Check the the brushes, they need to be long enough the make solid flat contact with the commutator.
If the brushes are worn out, any good automotive starter rebuild shop should be able to source some, if they have the dimensions of your brushes.
I've thought it would be a fun project to turn my motor into a brushless inrunner, by bringing all winding connections outside the case, and hooking them up in a 3 phase configuration.
My first ever ebike motor was a brushed 250w rated AOTEMA brand (sold by Green ebike kit I think) I got in like 2008-ish.
I still have it (pics below)
It is either burnt out (windings look fine from your pic) or, the brushes are worn out, or the segmented commutator ring needs serviced.
Brushed motors are generally easy to service if they have not been too abused.
This is probably what yours looks like under the stator;
Under the freewheel side;
Stator, the four red arrows point at the screws that set the timing for the brushes, probably don't mess with them;l
Stator, freewheel side, red arrows point to the carbon brushes, these slide on the copper segmented commutator.
This motor did not get a lot of heavy use, so the carbon brushes still have some service life left in them.
To service this motor; (or any dc brushed motor)
1. Disassemble, inspect the brush holders to make sure they are not burnt / melted / bent.
2. Check continuity of the windings with a multimeter, place probes on diametrically opposite commutator segments. (same position the brushes would be)
3. Check that the bearings rotate freely.
4. Inspect the commutator, it needs to be relatively flat, no excessive grooves or pitting. You can service the commutator by using a piece of fine sandpaper, or emery cloth(think 300 grit or finer) and polish it until it is nice and shiny.
EDIT; After polishing, run a razor blade or o-ring pick(or similar) between the commutator segments to clean them out.
5. Check the the brushes, they need to be long enough the make solid flat contact with the commutator.
If the brushes are worn out, any good automotive starter rebuild shop should be able to source some, if they have the dimensions of your brushes.
I've thought it would be a fun project to turn my motor into a brushless inrunner, by bringing all winding connections outside the case, and hooking them up in a 3 phase configuration.
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A-DamW
10 kW
THANKS SO MUCH! man, this is such good info thanks for helping!
No, it did not turn before i disassembled it But i think that was because it wasnt put properly back together due to one side of the motor not having any screws and not placed on properly
So i cleaned up most of the rust and all the parts, but i have one problem and that is that one of the brushes is worn way more down than the other which seems like it wont make contact with the commutator. how do i replace thjem and is there anywhere online where i can buy them?
The brushes don't look that bad. The commutator will be pretty close to the brush holder when it's assembled. When they wear down to the spring, they're gone. It would be hard to find those exact brushes, but you can often find ones that are about the same size or slightly bigger and sand them down to fit.
Can you pull the brushes out? I might just be the spring is weak.
How does the commutator look? Probably a good idea to clean it up.
Can you pull the brushes out? I might just be the spring is weak.
How does the commutator look? Probably a good idea to clean it up.
commutator is good, but i dont know how i can pull the brushes out because they are attached to a wire on the other side.
Thanks again i tested it after i cleaned all the rust and everything and the motor works perfectly!
That's great. I wouldn't worry about the brushes, as they look like they have lots of life left.
One more question, what would the estimated speed be for my motor? it looks a lot bigger than 250w so im estimating it could be a 1500w?
I wouldn't push it too much. Those might be ceramic magnets, which can be demagnetized by too much current. I'm not sure how you could test the magnets unless you have a gaussmeter.
A-DamW
10 kW
The only way to find out, aside from going for a test ride, is to measure.
Does your controller work at like 12 volts?
If you can spin it slow enough to manually count rpm at a fixed known voltage(full throttle), you'll
have the unloaded Kv.
Do you have access to a tachometer?
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Eric G
1 kW
I have an old Crystalyte 409 brushed motor that looks pretty much like the this one shown above.
I got it used and ran it in a 20 inch wheel and got over 10,000 kms on it before retiring it.(bike & battery 56lbs and me at 120lb)
I ran at 36 volts sla 25 amp controller and on a warm summers day I'd get to 40kmh.. 48volts would boost the speed some But I wouldn't run any higher than that without worrying that something was gonna melt..
I got it used and ran it in a 20 inch wheel and got over 10,000 kms on it before retiring it.(bike & battery 56lbs and me at 120lb)
I ran at 36 volts sla 25 amp controller and on a warm summers day I'd get to 40kmh.. 48volts would boost the speed some But I wouldn't run any higher than that without worrying that something was gonna melt..
